I'll add my own story, which is not intended to turn this into a thread full of disillusioned vets.
I qualified in summer 2009 and worked in 2 mixed practices in Northern Ireland and West of Scotland.
I do not think I was unlucky with my jobs: I had bosses who were on the whole, ok; Lunch was missed only occasionally (more often in the spring) the remuneration was good - 25K + accommodation (which I think is around average for starting. It does vary though and of my friends, the worst starting salary was 17k + accom, best was 32k, no accom)
However, things that Ponyvet mentioned take their toll and I also found myself pretty dissatisfied with the life I was having.
Days are long -average of 10 hours or more- and tiring - both mentally and physically (large animal particularly). On call can be awful- working over the weekend and through to Monday evening is 70 hours straight with no guarantee of any meaningful sleep. Driving then becomes dangerous etc, you make clinical errors due to fatigue, your people skills are tested to the max when tired and irritable. You are asked to bend over backwards for clients and they don't thank you for it because they've never known any different.
You come home from work knackered and starving. You sit in front of the TV, have dinner, a beer (unless you're on call) and then go to bed so that you stand any chance of waking up in the morning ready to start again. Even weekends that you're not working you are so tired that going out with friends is an effort. Social life definitely suffers.
The "every day is different" cliche is a untrue, from my experience. I find the job quite repetitive. Occasionally an interesting case comes along, but they are often referred (if insured) or euthanized (on cost grounds)
Clients don't listen properly to your advice or, worse, completely ignore it. They complain about the costs so often that any good feeling from a job well done is often extinguished by a comment about how "with the prices you charge no wonder you are so well paid".
Having said all this, you get lots of vets who love their job. You can do as much work experience and EMS as you like but at the end of the day, you won't know if its for you until you actually do the job. Which is unfortunate because its a lot of time, money, and effort to invest to realise 12 months later it's not for you.
I am currently looking to move from clinical practice into lab/research/academia. My degree won't be completely useless, but if I could have my time back I would not study veterinary medicine.